Study of inclusive electron scattering scaling using the generalized contact formalism
Abstract
The relative abundances of shortrange correlated (SRC) nucleon pairs in atomic nuclei are typically extracted from measurements of the pernucleon inclusive electron scattering crosssection ratio of nucleus $A$ to the deuteron, $a_2=(\sigma_A/A)/(\sigma_d/2)$, at high$x_B$ and large$Q^2$. Despite extensive measurements, theoretical calculations of $a_2$ are sparse. Here we study the sensitivity of $a_2$ to the abundance of SRC nucleon pairs using the generalized contact formalism (GCF), which successfully describes nucleon knockout from SRC pairs up to 1000 MeV/c of initial momentum. The GCF reproduces the measured plateau in the crosssection ratio and the values of $a_2$. However, using a nonrelativistic instantform formulation, the data are only reproduced using model parameters that are inconsistent with abinitio many body calculations. The calculations also show large sensitivity to the model parameters. Using a lightcone GCF formulation significantly decreases this sensitivity and improves the agreement with abinitio calculations. We conclude that empirical SRC pair abundances extracted directly from $a_2$ measurements cannot be regarded as having accuracy that is better than $\sim 20\%$ and that precision studies of the nuclear mass and asymmetry dependence of SRC pair abundances must rely on crosssection calculations that properly account for relativistic effects.
 Publication:

arXiv eprints
 Pub Date:
 May 2020
 arXiv:
 arXiv:2005.01621
 Bibcode:
 2020arXiv200501621W
 Keywords:

 Nuclear Theory;
 Nuclear Experiment
 EPrint:
 6 pages, 3 figures, 1 table, and online supplementary materials